A man dressed in a gorilla costume was shot with a tranquiliser dart after being mistaken for a real gorilla at a Spanish zoo, according to reports.

The staff member at Loro Parque in Tenerife was reportedly dressed in an ape suit for a practice drill when he was accidentally shot with the dart filled with enough drugs to take down a 400lb gorilla.

According to La Opinión de Tenerife newspaper, the employee was running around the zoo in the costume to add realism to the drill practicing what would happen if an animal escaped.

The disguise was probably more convincing than this (Picture: AFP / Getty / File)

But an apparent lack of communication led to the veterinarian, who has worked at the zoo for around two months, opening fire on the man during the incident on May 2, La Opinión reports.

The man suffered an allergic reaction to the dart and was taken to University Hospital of the Canary Islands where he is reportedly in serious condition.